bug#22689: [PATCH] Add logcount

[Eli Zaretskii]

> Date: Sat, 30 Sep 2017 13:07:58 -0400
> From: Mark Oteiza <mvoteiza@udel.edu>
> Cc: 22689@debbugs.gnu.org
> 
> Ok.  Patch including this, Benjamin's catch, and documentation.

Thanks.  A minor comment on the docs:

> +@defun logcount integer
> +This function returns the population count of @var{integer}: the
> +number of ones in the binary representation of @var{integer}.

I would mention here the "Hamming weight" term (in @dfn) that is
referenced in NEWS, and I would also add a few index entries:

 @cindex popcount
 @cindex Hamming weight
 @cindex counting set bits